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West Elk Mine <br />• Several published fracture research papers (Lorenz, et al 1991; Lorenz and Finley, 1991; Grout <br />and Verbeek, 1985; Diamond, McCulloch and Bench, 1975) indicate the problems of using <br />photo-linears for fracture identification and in projecting that information into the subsurface. Of <br />even greater significance to potential hydrologic consequences and the concerns of water moving <br />vertically through the alternating sandstones, shales, mudstones and coals of the Mesaverde at <br />the West Elk Mine are their conclusions concerning the vertical discontinuity of observed <br />fractures in surface outcrops and sub-surface cores. <br />Recent published and unpublished reports by H. Maleki and W. Koontz (1997), J. Corbett <br />(1997), A. Mayo (1998, 2000, 2004), R. Hams (1998), and S. Herron (1998) provide insight into <br />the chazacter, distribution, and water bearing capacity of the major tectonic fault systems. <br />Quotes and a brief discussion from some of the papers follow: <br />H. Maleki and W. Koontz (1997) studied the joints and cleats as observed in the B Seam mine <br />works and concluded "The predominate jointing of the sedimentary rocks is N 68° E to N 74° <br />E, with secondary jointing at N 28° W and N 35° W. As mining and exploration extend <br />farther east and south, more faults are being discovered. The faults trend almost parallel to <br />the major joint direction with offsets up to 2.Sm up thrown to the east " <br />In an interpretation of the airborne magnetic survey J. Corbett (1997) summarizes "The <br />newly-defined deep intrusive anomaly, centered south and east of Somerset, is interpreted to <br />• have several deeply buried cupolas, rising from a deeper larger source, that cause the two <br />broad lobes of the magnetic anomaly. Most likely the tops of the cupolas are 6,000-10,000 feet <br />below the surface and do not extend into the near surface." <br />S. Herron and D. Bagley in the Steffen Robertson and Kirsten report (1998) analyzed the <br />structural data available and concluded "These intrusive are likely to have caused doming of <br />the overlying Rollins Sandstone and coal measures during emplacement. The small- <br />displacement normal faults in the coal measures are interpreted as expressions of this <br />doming." <br />The seven major fault systems are identified from north to south as Unnamed, Oliver No. 2, B <br />East Mains (BEM),14HG, West Flatiron, Deep Creek, and Gunnison zones. Two of the seven <br />zones are not positively identified in the mine works but inferred from seismic and analytical <br />techniques. Two of the known five zones, BEM and 14HG, Gave exhibited displacement <br />greater than five feet and are strong conduits for water and methane gas inflows. The <br />Unnamed, Oliver No. 2, and West Flatiron fault zones are low displacement fault and fracture <br />zones that have limited water-bearing capacity. Fault waters are described more thoroughly <br />in Section 2.04.7 under the discussion of Groundwater Quantity Characteristics. <br />E Seam mining in the South of Divide permit revision area will encounter at least two known <br />and possibly two inferred fault systems. Provisions for safely crossing these faults include <br />modifications to pillar and crosscut layouts, additional roof support appliances, and <br />additional floor to roof standing support. <br />2.04-35 Revised November 2004 PRIO <br />